Correct Answer: Option C

Explanation

\(\cos (x + y) = \cos x \cos y - \sin x \sin y \)

\(\cos (60 + 45) = \cos 60 \cos 45 - \sin 60 \sin 45\)

= \(\frac{1}{2} \times \frac{\sqrt{2}}{2} - \frac{\sqrt{3}}{2} \times \frac{\sqrt{2}}{2}\)

= \(\frac{\sqrt{2} - \sqrt{6}}{4}\)

• can a commercial student study transport management or development studies in uniosun? Answer this

  2 Answers   ·   4 weeks ago
• an argumentative essay to support the motion that says technical and vocational education should be mandatory in secondary school in... Answer this

  2 Answers   ·   English Language   ·   4 days ago
• who is the was the first nursing mother of the prophet(s.a.w)? Answer this

  1 Answers   ·   CRK/CRS   ·   2 days ago